The passenger side power windows on my 2002 GMC Yukon 4X4 quit working. What could it be?
Windows being the plural form of the word is important. We know that both the right-front and right-rear power window motors are inoperable. Since it's uncommon that two power window motors burn up at the same time, we need to find out what the two components have in common.
I pulled up the appropriate wiring schematic with the ALLDATA information system. The window motor circuits are a bit complex, so I'll try and keep it simple. Both the R/F and R/R power window motors receive power (12volts) and a path to ground through the R/F and R/R window switches, while the master window switch (driver's door) supplies just a ground circuit to the front and rear switches to remotely trigger the two passenger side windows.
The windows go up and down by reversing polarity to the motors (switching positive and negative). There's not a whole lot in common with the two windows in question until we take a look at the main power sources for both. 12volts is coming from what's called the RAP#2 relay, while the L/F and L/R windows get power from the RAP#1 relay. A failure at RAP#2 or its related wiring and components does explain why both windows on the right side don't work, but the ones on the left do.
RAP stands for Retained Accessory Power and the relays are controlled by the ignition switch and the Body Control Module (BCM). RAP#2 relay is located in the fuse block on the right side of the instrument panel and there's a 50amp fuse marked RAP#2 you can check in the fuse block under the hood. We could guess at the exact point of failure, but the circuits should be tested by a pro before replacing any parts.